1. Field of the Invention
This invention relates in general to devices to deter rapid re-engagement of valve opening mechanisms, and more particularly, to an improved delay flush control forming part of a diaphragm flush valve used in a toilet, urinal or similar plumbing fixture.
2. Prior Art
Flush valves, and in particular flush valves used in the construction of water closets or urinals, have been used for many years. See, for example, U.S. Pat. No. 30,462 issued Oct. 23, 1860. However, the forerunner to one of the most popular modem diaphragm flush valve designs is disclosed in U.S. Pat. No. 1,714,573 issued May 28, 1929, and commonly referred to as a diaphragm flush valve. One problem with the diaphragm flush valve is controlling the amount of water used when the plunger handle is continuously being activated. This problem is particularly acute in prisons and schools where the persons using the toilet facilities are more likely to misuse the equipment. Principle causes of this problem are holding the plunger handle down for an extended period of time or continuously engaging the plunger handle which unseats the relief valve before a normal flushing cycle has been completed. A modified relief valve which addressed the first cause of this problem and other problems is disclosed in co-pending U.S. patent application Ser. No. 09/152875 entitled "Improved Relief Valve" and filed on Sep. 14, 1998 by the inventor herein. This invention addresses solutions to the second cause of this problem.
Over the years, improvements have been made to the diaphragm flush valve to provide control of the rapidity of the flushing operation employing electronic controls or mechanical controls. However, these improvements involve more complex and expensive construction than is desired by the industry. A second disadvantage of these flush valve designs is that they did not permit a simple retrofitting of the flush valve already installed, but required a more expensive replacement of an otherwise workable flush valve.